On August 1, 2008, iLounge published iPhone Gems: Every Sudoku Game, Reviewed, a feature article looking at 23 different Sudoku releases for the iPhone OS. This review focuses on Sudoku ($3) and Sudoku (Free) by Mighty Mighty Good Games; you can read the full article, with screenshots of all of the games together, through the link above. A collective screenshot below shows you some of the other Sudoku interfaces you can expect to find in these titles.

If you’re reading this article, you probably already know that Sudoku is a one-screen puzzle game based upon a 9-by-9 grid that’s partially filled with numbers. The objective is to fill the empty spaces of the grid with single digit numbers so that the same digit does not appear twice on any horizontal or vertical line. Additionally, the same number should not appear twice in any of nine 3-by-3 mini grids on the screen.

iLounge’s top-ranked Sudoku games are ones that offered fully-functional renditions of the game, with impressive interfaces, bonus features, user customization, and pricing as of the time we tested them. The fewer of these features a given game had, the lower it rated. While updates to these games may well be released over time, and their features may change, we couldn’t wait around forever for bad or so-so titles to catch up with ones that were already good or great.

Sudoku by Mighty Mighty Good Games is another mostly no-frills take on the game. Its biggest feature is the ability to change the color scheme to one of ten plain combinations; four levels of difficulty are included, as are a fairly limited array of 200 puzzles. You can make an italic font note as to what you think a square might be, receive hints, and compete against the timer, but there aren’t sophisticated space markers or other options here. The game is silent and accepts iPod music.

There’s also a free version of this app called Sudoku (Free) which has only three color swaps and doesn’t promise as many puzzles. Neither is great, but our advice would be to stick with the free one unless the $3 version becomes substantially better over time; both are demo-worthy, one charges you for that quality.

Editors' Note: iLounge only reviews products in "final" form, but many companies now change their offerings - sometimes several times - after our reviews have been published.
This iLounge article provides more information on this practice, known as revving.